nix-shell -p disko
sudo disko --mode disko --flake git+https://git.bulthuis.dev/Jan/dotfiles#<system>
sudo nixos-install --no-channel-copy --no-root-password --flake git+https://git.bulthuis.dev/Jan/dotfiles#<system>

If nixos-install is being stopped by the OOM-killer, you can try adding -j 1 to limit the amount of jobs that will be executed at the same time to 1. It might require running nixos-install multiple times untill it has managed to download all requirements and slowly start building the rest of the system.

Updating

To update the system configuration, it is a single command:

sudo system-update

Or if this shell script has not been installed for some reason:

sudo nixos-rebuild switch --flake git+https://git.bulthuis.dev/Jan/dotfiles

Sometimes it may be necessary to reboot of course.